Train control



y 7 c. s. BUSHNELL TRAIN CONTROL Filed Oct. 15, 1923 5 Sheets-Sheet 1 FIG 1 I 15 19 52 C? ZI V NTOR. J

May 10, 1927. 1,628,453

C. S. BUSHNELL VTRAIN CONTROL Filed Oct. 15. 1923 5 Sheets-Shoot 2 F|G.3. 5 5 5a a INVEN TORr May 10,1927. 1,628,4

v c. s. BUSHNELL TRAIN CONTROL Filed Oct. 15, 1923 5 Sheets-Sheet 3 a Z INVENTOR. 12%

14? ORNEY May 10 1927.. 1,628,453

C! S. BUSHNELL TRAIN CONTROL Filed Oct. 15, 1925 5 Sheets-Shut 4 FIGS.

I a INVENTOR. 1-

y 1927- c. s.- BUSHNELL TRAIN CONTROL Filed Oct. 15. 1923 5 Sheets-Sheet 5 Flall.

an -I W ORNEY IN V EN TOR.

Patented May 10, 192?.

CHARLES S. BUSHNELL, OF ROCHESTER, ll'EVf O I, ASSIGNOR TO GENERAL RAIL- WAY SIGNAL COMPANY, OF ROCHESTER, NEW' YORK.

TRAIN CONTROL.

Application filed October 15, 1923.

This invention relates to speed control systems of the time-distance interval type, and to certain new devices forming major elements of such a system.

In providing speed control systems for railways, it is found that certain locomoti ves are at times used in passenger service and are at other times used for moving freight trains. F or well-known reasons, a train made up of freight cars (especially if loaded) is much more difiicult to stop than is a passenger train, so that, other conditions remaining the same, found necessary to restrict the speed of a freight train. more than a passenger train in order to bring it to a stop, or to a predetermined low speed, before reaching a danger b'ei ilfill. Also, a safe and proper stop of a freight train provided with the usual type of air-brake equipment requires a greater degree of skill because of the varying conditions of grade, slack between cars, and the like, under which a brake application must be made, and for which ordinary automatic apparatus can not provide.

With the above and other considerations in mind, it is proposed in accordance with the present invention to provide a system of train control in which control influences are transmitted from the trackway to a moving vehicle through an intervening air gap, which is designed and constructed in accord auce with the closed circuit principle, so that the interruption of any circuit causes an automatic application of the brakes; to provide a circuit arrangement including a circuit for energizing a primary exciting or field coil, the field of which is an essential for the proper operation of the system and is checked against an open, and the depreciation of the current flow in the circuit due to a failure of the source of supply, or the like.

Further, the circuit arrangement proposed is such that a short between turns in this exciting coil or a shunt around this coil will produce an effect upon the system which causes an automatic brake application. Also. the decrease of current through the exciting coil, due to an increase of contact resistance of certain contacts in series therewith, produces a similar effect, which also causes more sensitive operation of the system so as to assure the transmission of a control influence when passing an active trackway do Serial No. 668,665.

vicc. Next, the proposed car-carried equip ment consists of a circuit arrangement which is checked so that an open or a detrimental decrease in current flow in any circuit and the shorting or detrimental shunting of the exciting coil produces an automatic brake application.

As a further object and purpose of the present invention, it is proposed to provide a time-element device to control certain circuits in a certain sequence if initiated, in which the time cycle may be adjusted for freight or passenger service as required; to provide a brake valve actuator which may be attached to the usual engineers brake valve which if actuated causes an effective and unpreventable brake application when set for passenger service, and which actuates the usual engineers brake valve in a manner so that the engineer may forcibly prevent or forestall an automatic application of the brakes when adjusted for freight service, so that the engineer may make a partial brake application to bunch the slack which may be followed by a full application of the brakes when used in freight train service.

A still further object of the present invention contemplates the provision of a time element device which will actuate the engineefis brake valve if two successive control influences are transmitted from the trackway in less than a predetermined period. of time, in which the time constant of the device may be adjusted for passenger and freight service respectively, this adjustment being interlocked with the brake valve actuator so that the time-element device and the brake valve actuator must both be adjusted for either passenger or freight service.

Other objects, purposes, and characteristic features of the invention will appear as the description progresses.

In describing the invention in detail, ref erence will be made to the accompanying drawings, in which Figure 1 is a plan view of the usual engineers brake valve with a valve actuator embodying the present invention applied thereto, a portion thereof being broken away to illustrate passenger and freight changeover mechanism;

Fig. 2 is an elevation of the device shown in Fig. 1, with parts broken away on substantially a center line through the valve actuator, and illustrates, an electro pneu- Lil matic valve connected theretofor controlling the same;

Fig. 3 is a horizontal section of the device taken on the line 83 Fig. 2, as viewed in the direction of the arrows;

ei is a similar view of the device taken on the line -l-4 Fig. 2;

Fig. 5 is a partial sectional elevation of an actuator taken on the line Fig. 4:, as viewed in the direction of the arrows:

Fig. 6 is a horizontal section of the device taken on the line 6 6, Fig. 2;

Fig. 7 is a plan view of a time-element device embodying the present invention parts thereof being broken away to illustrate the construction of the contact mechanism;

Fig. 8 a side elevation of the device shown in Fig. 7' with parts thereof broken away substanti lly on the line through the axis of the device;

Fig. 9 is a horizontal section taken on the line 99 Fig. 8, as viewed. in the direction of the arrows;

Fig. 10 is a horizontal section taken substantially on the line 1010 Fig. 8, as viewed in the direction of the arrows; and

Fig. 11 illustrates an exploded view of the various essential elements of the timeelement device certain responsive devices and a circuit arrangement of the train control system embodying'the present invention.

iii'fw-"uc/"uwe of magi/reefs bl'alire 'vaZ e actuator and control cal 0c.

Referring to Figs. 1 to 6 inclusive of the drawings, an engineers brake valve actuator embodying the prer-1e11t invention is shown applied to the usual engineers brake valve which is controlled by a suitable electro-pneumatic valve EPV. The body of the usual. engincefis brake valve has been illu atcd at '1. as provided with the usual cap :2. from the to of which. projects the usual valve stem 8. This valve stem 3 is squared atthe end to receive the usual enginecr s brake valve handle or the actuator embodying the present invention as desired.

The actuator comprises a casing (l terminating in oppositely disposed cylinders at and 5 and having a semi-circular extending base consisting of two arcuatepieccs (3 and 'T connectml by two vertical ribs 8 (see Figs. 5 and (S). In the top of this casing C is a hole in which is pivotally supported changeover mechanism for setting up means so as to cause an unpreventable brake application for passenger service or to cause a permissive brake application for freight service, as desired. 'lhis changeover mechanism comprises a change-over plate 9, to opposite sides of which are riveted a cam 10 and a lever 11, respectii ely, by rivets as shown. This change-over plate 9. is also provided with a downwardly extending portion which forms a journal for pivotally supporting suit-able apparatus presently to be described. In order to provide proper lubrication about this journal an oil hole has been pro- "ided, as shown which is normally closed by a screw This passenger to freight change-over plate 9 is provided with a skirt to which is fastened a contact comprising a ring l3 oi insulating material, to which is fastened a contact segment ll by suitable rivets as shown (see Fig. 5) said segment extending partly around the insulating ring (see Fi l). The back of the actuator casing C Fig. 1) is provided with a rectangular opening, which is normally closed by a conduit outlet 15 through which suitable wires are brought from a flexible conduit 16 (Fig. 5). This conduit outlet 15 has screw f toned thereto a block of insulating material 17 to which are riveted spring contact lingers 18 by eyelets 19 the wires 20 being passed through these eyelets and fastened to said fingers.

lVith the changeover handle 11 in the passenger position as shown the contact fingers 18 are bridged. by the contact segment If however, the change-over handle ll moved. to the other extreme or freight service position the segment 1st is out of contact with one of these contact fingers 18, thereby interrupting a circuit including these wires 20.

The change-over handle may be locked in either of its extreme positions to perforated projecting lugs, as shown, (see Fig. 1) by a padlock seal or the like so that it may either be set to the proper positions and locked there only by persons authorized to do so or if sealed it may be changed by the engineer by brcaning such seal, which serves as a tell-tale as desired.

A valve actuator sleeve AS. having a square hole in the bottom thereof and fitting on the valve stem 3 has its upper end pivotally supported on the downwardly projecting journal portion of the change-over plate 9. therewith oppositely disposed arms 2]. and TBSPGClilYGl); (sec 3 and 4i) the tlunctions of which will be more fully explained hereinafter. The arm 22 provided with a hole in the side thereof forming a pocket to receive the end of a compression coil spring 23 (see 4) z and the other end of this spring seats in a similar hole in a latch 24- pivotally supported between the cars 25 extending from the actuator sleeve AS so that the latch is yieldably held in the position shown.

The actuator sleeve AS has pivotally supported thereon a gear sector 27, which is limited for endwise movement by a shoulder on the actuator sleeve ll- S and by the changeover cam 10 Fig. 2). This gear sector lli'i lil) This actuator sleeve AS has integral 27 has a headed unlatching pin 28 slidably supported in the web of this gear sector; and this pin is urged upward by a spring 29 (see Figs. 2, 3 and against the cam surface of the cam plate 10. It should be noted that this cam plate l0 has part of its l)tlll]I)llGlY cut away (see Fig. 3), so that the head ot the unlatchiiiig pin 28 rides against the surface of the cam plate 9 for all positions of the actuator under freight service conditions, but rides on the cam portion of the change-over cam 10 for all positions of the actuator under passenger position of the change-over handle 11. In other words, the unlatching pin 28 extends from the bottom of the gear sector when the apparatus is set for passenger service, but does not project from the bottom thereof when it is set for freight service.

This gear sector 27 is actuated automatically, and in the particular embodiment of the invention shown is actuated by a differential piston operating mechanism, comprising a large piston 31 contained in the large cylinder 5 and a small piston 32 contained in the small cylinder 4. These pistons are provided with the usual. piston rings, gaskets, and clamping devices well known in the art. These pistons 31 and 82 are sup ported on the ends of a rack 33, and are adapted to move endwise by pressure in the cylinders 4i and 5 until they engage the screw plugs 34- or 35 of the cylinders l or 5, respectively, and are prevented from turning by reason of the engagement of the rack 33 with the gear sector 27. The cylinder 4.- is connected to main reservoir pressure, as shown by MR, by a pipe 36, whereas the large cylinder 5 may be connected to main reservoir pressure or to atmosphere through a pipe 37 by a suitable electro-pneumatic valve EPV to be described hereinafter. From the gear sector 27 projects a downwardly extending lug 40, which is of a length so that it may engage the arm 21 extending from the actuator sleeve AS.

On the lower end of the actuator sleeve AS is pivotally supported a handle plate HP (see Fig. 2), which is limited. in its upward movement by a shoulder on the actuator sleeve AS and by engagement with an inwardly extending flange 42 extending from the casing C. This handle plate HP is held up in position by a retaining plate RP, having two radially extending legs 43 and t4 faslended to the actuator casing C by cap screws as shown (see Figs. 2 and (3).

This handle plate HP is provided with an upwardly extending semi-circumferential rib 46 (see Figs. 2, 3 and 4:), which has its one end tapered so as to cooperate with the end of the latch 24 while the apparatus is in its normal condition. This handle plate HP is also provided with an upwardly extending lug 47, which under normal conditions engages the arm 22 extending from the actuator sleeve AS (see Figs. 4 and 5). This lug 47 does not extend far enough to interfere with the lug d0 projecting down from the gear sector 27, so that both the lug ll) and the lug ly? may engage this arm 22 (see Fig. 5) without interference.

it should be noted that movement of the rack 33 from the right toward the left causes movement of the gear sector 27 in a counter-clockwisedirection, and that a certain amount of movement of this gear sector is possible before the projecting lug 40 on this gear sector engages the arm 22 on the actuator sleeve AS. This amount of lost.

motion is provided so that the engineers brake valve handle 50, which is integral with the handle plate HP, may be moved from the normal running position as shown to the release position (see Fig. 4) without causing engagement of the arm 22 with the lug 40. If the gear sector is actuated in a counter-clockwise direction by the rack and associated pistons, the valve proper of the usual engineers brake valve will assume the service position as the piston 31 engages the screw cap 85. If, however, this movement of the automatic apparatus moves very fast, the inertia of the parts might possibly carry the valve proper beyond the service position; and in order to avoid this contingency, a suitable stopping or counteracting mechanism has been provided.

In the embodiment of the invention illustrated, a stop arm 51 is pivotally supported by a pin between ribs 52 extending from the back of the casing C. This stop arm 51 is of the peculiar shape shown (see Fig. 4), and is provided with a limiting pin 53 which limits the movement of this arm 51 in the clockwise direction by reason of engagement of this pin 53 with the upstanding rib d6 of the handle plate HP. As the rack 33 and associated parts are moved to the brake applying position, the piston 32 engages the rounded portion of the arm 51 and urges this arm to the position shown in the drawings (see Figs. 3 and t) by a force depending on main reservoir pressure and the size of the piston 32. As the actuator sleeve AS is moved in the counterclockwise direction by the rack 3%, the pin 5% riveted into the arm 22 extending from the actuator sleeve AS engages the cam portion shown at 51 and is opposed and resisted from further movement by reason of this stop arm 51. If desired, the engineer may, however, force the actuator sleeve AS to the emergency brake applying position; and in order to avoid overthrowing of the alve proper beyond the emergency position by the engineer when the handle plate HP is unlocked (as will more clearly appear hereinafter), the stop arm 51 has been provided with a hook 51 for limiting the movement of the sleeve AS beyond the emergency brake applying position.

As heretofore mentioned, the small cylinder a is continuously connected to the main reservoir and the larger cylinder 5 is at times connected to main reservoir pressure, and is at other times connected to atmos phere. This arran ement is used so that with the same pressure in both of the cyl inders, the larger piston 5 overpower-s the smaller one and causes the rack to be moved toward the righthand position as shown; and if pressure is released from the large cylinder by connecting it to atmosphere, the pressure in the small cylinder 4 causes an automatic actuation of the apparatus. It is thus noted that the force for actuating the apparatus is always present by reason of the presence of main reservoir pressure in any air-brake system when in use, so that the two cylinders with differential pis tons are constructed on the side of safety, that is, a failure of air pressure in the cylinder 5, which the cylinder that is controlled, will cause an automatic application of the brakes, failure of pressure in the small cylinder 4 being highly improbable and practically impossible.

In the particular construction shown, the electro-pneumatic valve EPV for control ling the flow of main reservoir pressure to the small cylinder 4 or for connecting the cylinder to atmosphere, comprises an electro-pneumatic valve consisting of a top or valve portion, and a bottom or actuating portion. The valve portion comprises a chamber having three compartments 60, 61 and 62, respectively. The middle compartment 61 is connected to the cylinder 5 by a pipe 37, whereas the top compartment 60 is connected to the main reservoir by a pipe 64, and the bottom compartment (32 is connected to atmosphere by a port 65'. The partitions between the several compartments are provided. with tapered openings forming valve seats to cooperate with valves 66 and (37, respectively. These valves 66 and 67 are rigidly secured to a valve stem 68 slidably supported in the screw plug 69, in a manner so that when one valve is closed the other is open. This valve stem 68 is normally urged downward by a spring 70 contained in the bottom compartment between the partition and a collar 71 pinned to the valve stem.

The actuating portion of the electro-pneuiiiatic valve EPV comprises an iron-clad electro-magnet, consisting of a magnetic casing 75 supported on the main casing of the valve in any suitable manner. This magnetic casing 75 is closed by a cover 76 of non-magnetic material, and contains a solenoid 77 in which is disposed a core 78 connected to the lower end of the non-magnetic valve stem 68. On the lower extreme end of the core 78 is a disc-shaped armature 79, which in its normal energized position is disposed ad acent the solenoid 77.

Operation 0; engineers brake ord 0e actuator and EPV.

Assume now that the electro-pneumatic valve EPV deenergized by suitable auto matic apparatus on the vehicle, possibly because of danger trafiic conditions ahead. Deenergization of the winding 77 causes the valve and associated valves to assume the lower position, whereby the valve (36 cuts off main reservoir pre sure from the compartment (51 and "the valve (37 connects this compartment 61 and in turn the cylinder 5 to atmosphere through the port 65.

As the fluid pressure in the large cylinder 5 decreases, due to the venting thereof to atmosphere, main reservoir pressure in the small cylinder l moves the pistons 3l32 and rack 83 to ard the left, thereby moving the gear sector 27 in a counterclockwise direction. A certain amount of idle movenieiit oi the gear sector, for reasons here tofor explained, will first take place.

Just before the lug 40 depending from the car 27 strikes the arm 21 projecting from he actuator sleeve AS, the unlatching pin 8, by reason of the fact that it is in its depressed position because the change-over handle 11 is in the passenger service position, rides under the cam surface of the change-over cam 10 and engages the upwardly extending part er of the latch 24, thereby actuating this latch, compressing the spring 28 and causing uncoupling between the actuator sleeve AS and the handle plate HP as far as counter-clockwise rotation of the cam sleeve AS is concerned. Just after this unlatching has taken place, the depending lug 40 of the gear sector 27 engages the arm 22 of the actuator sleeve and continued movement of the rack causes the actuator sleeve to be moved to the service brake applying position, whereupon the piston 31 strikes the screw cap to establish the ultimate position of the automatic apparatus. With the pistons 81-4-32 in their ultimate brake applying position, the piston 32 engages the stop arm 51 so that the momentum due to the inertia of the parts can not cause the actuator sleeve AS to be moved beyond the service position, this by reason of the pin 54 and the arm 22 of the actuator sleeve engaging with the cam portion of this stop arm Til.

If new the engineer wishes to effect an emergency application of the brakes, he may move the handle 50, thereby causing the handle plate HP to follow up the actuator sleeve A55 and when reaching the service position causing the lug l7 of the handle plate HP to engage the arm 22 of the actuator sleeve. By applying a considerable force, the engineer may cam the stop arm 51 Oil toward the right (see Figs. 53 and in opposition to main reservoir pressure acting against the arm 51; whereby it the pin 5% has passed oil? of the cam portion 51 no further opposition due to the stop arm it exists until the emergency position has been reached. Just a little beyond the position at which the handle plate forms an operative connection with the actuatmsleeve AS by engagement of the lug l? with the arm 21, the latch 24 will no longer be engaged by the unlatching pin 28, thus again locking the handle plate to the actuator sleeve A8 to allow the valve to be moved by the handle through a certain limited angle. For instance, if the engineer should. wish to release the brakes, he may move his handle in a clockwise direction and carry with it the actuator sleeve AS to the service position. As soon as the service position is reached, the latch 2 1? is no longer engaged by the unlatching pin 28 so that the operative connection between the handle plate and the actuator sleeve again broken, and movement of the engineers brake valve handle to the running or release position produces no effect because the valve itself will be held in the service position by the rack 83 through the medium of the lug l0.

Let us assume now that the apparatus is again in its normal condition, as shown in the drawings, and that the change-over handle 11 is moved to the other extreme or freight service position. Vs ith this handle ll moved the freight service position, a circuit is interrupted due to disengagement of the contact segment 14; with one of the contact lingers 18, for reasons .more fully described hereinaft r. Also, this movement of the change-over handle causes the chang over cam to assume a position so that the h rad of the uulatching pin 28 no longer is held in its depressed position, but may assume its upper position and ride on the under surface of the change-over plate 9 for all positions of the gear sector :27. If now the gear sector moved in a counter-clock wise direc ion, in a manner as heretofore explained, by the automatic shifting of the rack the unlatching pin does not strike the top portion 24 (see Fig. of the latch 24;, so that no unlatching between the actuator sleeve AS and the handle plate HP takes place.

It is thus noted that, with the freight set up, the engineer may oppose the force er;- erted on the actuator sleeve by holding the handle against n'iovez'nent. The diameters of .inders' and 5 so chosen that the the cylinder is licient to overcome the various iai'ts and move the a o the normal position, as shown, wth main reservoir pressure in both of these cylinders; and the cylinder 4 is large diameter of the cylinder 5 over that ing movement of the valve by the automatic apparatus.

The handle 50 integral with the handle plate HP is provided with the usual latch spring pressed outwardly by a compression coil spring 56 contained in the handle. This latch 55 is adapted to engage suitable notches in the quadrant 2 on the cap 2 of the usual engineers brake valve for the purpose of facilitating the movement of the brake valve to the different positions. A suitable thumb trigger 5? is pivotally supported from the handle 50 by a pin; and to this thumb trigger 57 is pivotally secured a tapered plug 59, which is adapted to be forced into a conical open ing in the latch member 55. Normally, this thumb trigger 57 is pressed outwardly by a compression coil spring 58 supported as shown; and if the engineer wishes to increase the force acting on the latch 55 in a direction to engage notches in the quadrant 2 he may press his hand or thumb against the thumb trigger 57, thereby forcing the tapered plug 59 in the conical opening and holding the latch 55 projected out of the handle.

This construction is provided so that when the change-over mechanism of the brake valve actuator is in the freight service position, andthe engineer wishes to hold off an application in order bunch the slack of the train or the like, he 1na force the handle hack to the running position temporarily, or he may hold it there permanently if he wishes, to avoid an auto matic application of the brakes. in order that the engineer may know at all times whether heis in the service or lap position, both of these positions being defiied by a single notch on the cover of the engineers brake valve, the thumb trigger has been provided to hold the latch 55 more forcibly projected. That is, the latching effect in the service-lap notch may be made more pronounced by pressing the thumb tripg or.

i 17:7726-6ZW72671 t decide.

'98, respectively.

ment of the present invention, comprises a balance wheel. n'iounted for rotation and urged to a certain intermediate position by a suitable spring but held in one extre :e position by an electro-inagnet; wherel ii? the electro-magnet is momentarily dceuergized the ba-lanc wheel started on a cycle of rotation and will rotate beyond the neutral position, thus tensioning the spring in the opposite direction, after which it will return to almost its initial pos"'on thus completing a cycle of operation illitl which it can again be held by the electromagne. The oscillation of the 'e wheel opens and closes circuits in c 11 sequence, whereby a suitable train control device is operated only if two successive impulses are received in less than a certain interval of time corresponding to one oscil lation of the balance wheel. The time inter val or cycle may be changed by loe and unloading the balance wheel in a simple and efficient way.

More specifically, this time-element device TE (see Figs. 7 to 10) comprises a cylindrical casing having a cover 87 with an inserted glass panel and a detachable base plate 87 ll ear the top of the casing is supported a spring housing SH containing a ball bearing 88 of the usual unitaryassembledtype. This spring ho ing SH is stationaryunder 1101 l operating conditions of the apparatus butis pivotally supported for rotation about a vcrti 'al axis for reasons more fully described hereinafter. The base plate 8. is provided wi h a similar ball bearing 89. The be l bearings 865 and 89 support a shaft 00 r rotation about a vertical axis; and to this shaft 90 is connected a balance or ineri-i wheel 91. In the particular embodiment of the invention illustrated v this balance wheel 9 t is fastened to the shaft 90 by a spring pressed friction slip clutch for the purpose of allowing a certain amount of sli; page if the shaft is suddenly accelerated or decelerated.

In the particular construction shown, this clutch comprises a pair of discs 92 and 93 spring pressed together by being engaged by one end of a compression coil spring 9a, which has its other end supported by a flanged washer 9?. A. disc of friction material 90 is interposed bQJWGQD the huh of the balance wheel 91 and the plates 92 and The upper plate 02 adjustably secured to the shaft 90 by a threaded connection as shown, and is n'ovided with axially extending teeth so that it may be locked in any adjusted position by a cross pin as shown, for reasons more fully described hereinafter.

The main vertical shaft J0 is shouldered near its upper end to support a s1 ring anchoring hub 98, which has a plurality of axially extending holes in its end face, any one of which may receive a pin 99 riveted to the contact operating sleeve- 100 splined lo ahe shall by a cross pin 3012. it will thus be noted that, when the contati (nunutin' sleeve 100 is moved upward on the sh the spring anchoring hub 98 may be ated with respect to the shaft to any one of various adjusted positions after which the contact o 'ierating sleeve 100 may be slid back in spiined engagement with the shaftand thereby fixedly secure the hub 98 to the shaft 90.

heretofore mentioned, the shaft 90 is used to a predetern'iined position by a suite spring. similar to the hair-sprin of a .rch. In the particular embodiment illustrated, this spiral spring 10% has its inside end fastened to the spr ng anchoring hub US by a pin 105, and has its other end riveted to the inside of the spring housing SH by a rivet 106 (see Fig. By reason of the "stab e connection of the spring anchori h hub 081:0 the shaft 90 the normal position o said sha: and the balance wheel 91 'PltZPliQtl to engage the saw teeth formed in top edge of the spring housing SH, in which position this clamp is held by a cover screw-fastened to this housing Ell-l, thus iiorining the wcll-hnown washliioard adjustable means for changing the effective length of the spring 10%. The mechanism of the time-element device Tl l thus far described v orises parts c rrespondi, in many respects to the well-known balance whcel used in chronometers.

Holding magnet. In addition to the balance wheel 91, the shaft 00 is weighted by an armature 108 supportedfrom the shaft and a counter-balance bracket 109 supported directly opposite this armature (see ll igs. and 10). This armature 108 is mad conditions held in the position shown in the drawings by a stz2;"ting or magnet HM. This holding lli'ilfl yoke 113 secured in place by nuts as shown. On each of these cores is a coil 11%,

these coils being conueced in series in a suitable circuit, more u ly described hereinafter. Secured to the side of the pole pieces 121 by screws shown F 8') 1s a bridge 115 of non-magnetic material This bridge 11.5 is cross'drilled and counter boreifh and contains a spring pressed. residual pin which is limited in morement in both directions as shown. This residual pin 111' when fully deprr :d into the noun terbored cavity projects outside of the bridge 11!) a sutlicient distance to maintain a small air gap between the armature and the pole pieces ill. for the purpose of preventing an excessive amount of residual magnetism which might hold the armature in the attracted position when the electro magnet HM is deenergized. The spring lO -l is secured to the spring anchoring hub in such a way that it tends to move the armature 103 to a position where it is displaced. between 100 and 120 degrees from its normal at acted position.

'l". thus be noted (referring particif) Fig. that deenergization of the coils 11 i allows the spring-pressed residual pin 116 to start off the armature, after which the mg 104- will our it to its biased posi i The inertia of the rotatable parts the armature substanwill. howercr Carry tially again as far {that is, 200 to grees} from its normal. attracted position, thereby tensioning the spring 101 in the opposite direction. After this position of armature has been reached, the spring il again return the armature back within a very short distance of the residual pin 116. If, by the time the armature reaches this positioin the holdi electronagnet HM is again energizer 103 will a ain be l nelu in snown 111 the drawof the holding n ce wheel 91 an: ie one osc ion "or which ll may be again locked the normal and held than b the cl r for another osciilat.

0 2cm 7 conic r in one to tain one circuit ti dining normal conditions of the upper i another circuit for a time v olre of a cycle of opera on of the time-element (l9- rice two contacts operable by the shaft are j'JlfOYlflGCl. One of thecontacts. conveniently called the n i. pen Conta and the other contact. conveniently cc th normally cl contact. tially the same and or co 1 of one it iencc like pa ofthesc co r ven lilre reference tr expon a being applied to a once character of the norm. contact. I In the particular construction shown (see the righthandcontacts of Figs. 7 and 9). the side wall of the casing K is provided with a large rectangular opening directly have been binding post 122 has adjustably fastened thereto a stationary contact 128, preferably of highly refractive conducting material, such as carbon, or the like, which is adapted to be locked in place by a lock nut.

To the contact operating sleeve is fastened a sector of insulating material 130, to which is riveted a cam or arcuate piece of metal 131. The contact operating sleeve 101) is held in its lower splined position by another contact operator 132 which is clamped to the shaft 90 by a cap screw 133. To this latter contactoperator is fastened an actuator 13% secured to a hub 132 but insulated therefrom by an insulating strap 135. Under normal conditions of the apparatus, the contact actuator 134: engages with the roller 127 and maintains the contact finger 123 in engagement with the stationary contact 128; whereas the arcuate piece 131 is not in engagement with the roller 127 except when the balance wheel is substantially in the middle of an operating cycle, and therefore contact finger 123 is normally out of engagement with the stationary contact 128. I

By looking at Figs. 7 and 9, it will be noted that if the holding magnet HM is momentarily deenergized, the balance wheel 91 and associated parts will complete a cycle of operation during which the contact finger 123 is released from the stationary contact 128 to open a circuit by movement of the mechanism in a counter-cloclmise direction as shown by the arrows. lVhen the balance wheel 91 has substantially reached its ultimate position, the arcuate segment 131 will engage the roller 127 and for a. time complete a circuit by reason of the contact finger 123 engaging the stationary contact 128. after which the balance wheel is'turned to a position to again open the contact finger 123"- and when it has substantially completed its stroke, 'will again complete the circuit including the contact finger 123 and the stationary contact 128.

Change of timing for freak ht and passer/.- ger.ln order to prolong the time necessary to complete the cycle heretofore mentioned, suitable means have been provided for weighting or loading the balance wheel 91 so that the'time necessary to accelerate and 'decelerate, the total weight is increased. In the particular construction shown, a cupshaped changeover weight 140 of magnetic material, having ,:a downwardly extending V-shaped flange 140 adapted 'to engagea V-shaped'g roove in the :balance wheel 91, is disposed above said balance wheel. This weightldO forms an armature of a suitable changeover magnet CM, which, it energized, raises the weight lromtheba'lance wheel 91, but it deenergized, .al-lows said weight to rest on the balance wheel 91, thereby increasing the mass tobe oscillated.

This change-over magent CM, in the particular construction shown, comprises aninverted cup-shaped piece of magnetic material l ll, forming the external magnetic.

circuit of an iron-clad electro-magnet, which is tr.stein-3d by screws or the lilteto lugs on the main casing .K. This inverted cup lll is provided with a threaded opening near the center thereof, in which is threaded a hollow core 142 surrounding-the shaft 90 of the time-element device. provided with an enlarged circular pole piece 142, which is rabbeted to support a ring 143 of non-magnetic material. In the annular pocket formed by the cup 141 and the core 142 is contained a coil 14A for controlling the change-over magnet GM. In orderto preventthe residual magnetism of the change,over magnetJCM l rom maintaining the change-over weight 1&0 of magnetic material in its raised position, even when the change-over magnet is deenergized, a residual plate 145 of non-magnetic material is interposed between these two devices. As heretofore explained, the clutch plate 92 may be adjusted to various elevations .by removing a. lock pin and turning this plate upon the shaft 90. This construction is provided so that the position of the balance wheel 91 with respect to the change-over magnet CM may be varied so asto facil'i tate the adjustment of the air gap between this magnet and the changeover weight 140, the, ring 1&3 of non-magnetic inaterial'being provided so that impregnating compound, or similar substance used .iorsaturating the coil ld l, can not work its way between the residual platelet") and the core 142.

From the construction of the apparatus just described, it is apparentthat energization of the changeover magnet. CM reduces the effective weight of the timing mechanism to the extent of theweight Pith-for the reason that said weight will be heldtirmly against the residual plate and will not interfere or retard the operation of the timing mechanism; whereas if thisnragnet CM is deenergiz ed, the weight letO will wholly rest on the balance wheel '91, and will increase the effective weight 01" the timing mechanism to thisjexten't.

Reset ,deoices.-The mechanism thus far timing mechanism to its normal position This core 142 is lending l i'Oln the spring housing SH. is

JI Vslidably supportel 160 adapted to be connected to suitable thud described comprises the essential parts of thetime control niechanisn'i liar as operating conditions are concerned. If, how ever, two suit e control. iinpul ccived in i the time c time-element device, as hereinafter ex plained, the armature lot; will stop in intermediate position; and it is i'iecessz'u'y provide a convenient way oi? restoring the this resetting apparatus being prcl erabl operable only from the ground.

In the particular construction shown, the )ring housing till is pivolaily secured in a coss-piece lit; l i 8 and 10) tastcncd to the casing li; and this spring housing is biased to one extreme poldtion, so that the stop lug k9 projecting from the bottom thereof engages the crossoiece 11 -8 by a spring 150, this spring having its one end coni'iccted to a pin 151 adjacent to the lug lei) and its other end secured by a screw 15? to a flange extending from the cross-piece l i-5:3. This spring 150 develops sullicient torque to maintain the spring housing in i s normal position as shown, regardless o the position of the armature 108 or the tension which may exist in the spring lO-l curcd a pinion 15 by a dowel screw 1. This pinion 153 in operative engagement with a rack 156 guided by an arm 112 extending from the nonanra netie cover 112.

To the extreme end of this racl: 156 is fastened a piston 158 provided with the u ual Tins nston i555 packing, or the Iii i intec cover plate 112. 112 closed by a screw plug 159, to which is connected pipc n a ili grai with the non-ma The end oi the cylinder pressure, such as the main reservoir pr sure ot' the usual air-brake system, designated MB.

Referring particr assume that the holdii gized but that the armat is in its neutral or intermediate position, substantially 110 degrees to the left of the position shown in the drawings. It now main reservoir pressure is applied to the cylinder 112 the piston 159 and rack 156 are moved to the left and turn the spring hous' 1g SH in a clockwise direction. Since the armature 108 is connected (at least yieldably) to the spring housing SH, the armature will aturally also move in a clockwise direction and is attracted by and eng es the pole pieces of the holding magnet rial when the racl;

-reaehes its ultimate position and the lug 149 engages the other end of the cross-piece 1&8.

ill)

phere, the spring 150 returns the spring housing SH to its normal position, thus ten- 'sioning the spring 104, because the armature 108 is maintained in its attracted position.

Reset coamoifzs'.ln order to make and break certain circuits for resetting purposes during the resetting operation mentioned, a double contact normally open reset switch DR shown on the leit side in Fig. 7 has been provided, this switch being closed substantially at the end of the operating stroke of the reset mechanism. This double contact normally open reset switch DR is constructed substantially the same as the operating contacts heretofore described (the corresponding parts being designated by the same reference numbers and an exponent c); but is provided with an additional contact 160 adapted to cooperate with a stationary contact 161 electrically connected. to a binding post 162. This double contact reset switch DH is provided with an insulating roller 168, which is engaged by the switch operator 16% riveted to the spring housing SH (see Fig. 7). It should be noted that this switch operator 164 is of such a shape that it does not interfere with the operators for the operating contacts, nor with the make-beiiore-break contact to be presently described. It will be noted that movement of the spring housing SH through an arc of substantially 170 degrees in a clockwise direction causes the switch operator 164; to engage the roller 168 to put this double reset switch DB in its operative position.

In order to make and break circuits in overlapped relation at the beginning and at the end, respectively, of the resetting. operation, a make-before-break contact MB has been provided (see Fig. 9). This makebe'tore-break contact comprises a pivotally supported finger 166 to which are riveted movable spring contact fingers 167 and 168. These spring contact fingers 167 and 168 are biased outwardly, and are limited in such direction by a double headed pin 169. The contact spring 168 is normally in en gagement with a contact on the binding post 170. The contact spring finger 167 is adapt ed to engage a contact connected to the bind-- post 171 when the finger 166 is in its other extreme position. The finger 166 itself is connected to a binding post 172, and is biased. and limited in its movement substan tially the same as the contacts heretofore,

described. The contact finger 166 is held in the normal position by an insulating roller 1725, pivotally secured to the spring housing SH, which engagesan arm 17 1 extending from this finger 166.

By looking at Figs. 7 and 9, it is apparent that a reset operation, comprising a movement of the spring housing SH in a clockwise direction through substantially 170 degrees back again to its normal position, causes the two contacts of the contact mechanism DR to be closed substantially throughout this cycle of operation, and causes the makebefore-break switch MB to be moved to an abnormal position and maintained there until the resetting operation is completed. The purpose of these resetting contacts will be more fully described in connection with the operation of the system shown in Fig. 11.

Reset UCZZ UG.*tXS above explained, the time-element device is restored to normal, after operation thereof due to excessive speed, by admitting and exhausting pressure from the cylinder 112 This is preferably done by manual operation of a reset valve accessible only from the ground. A si1n plified construction of reset valve RV for this purpose is shown in Fig. 11. Vfith the valve RV in the position shown, the cylinder 112 is connected to atmosphere; but when said valve is manually shifted to the dotted line position, pressure from the main reservoir is supplied to said cylinder, with the results above explained.

Other car-carried devices.

In addition to the brake valve actuator and the time-element device already describechthe car-carried apparatus includes a control relay CR, a secondary relay SR and a brake control relay BR which have been conventionally illustrated in Fig. 11. These relays are all of the traotive type, and are provided with balanced armatures supported on vertical pivots so that jar and vibration will not have a tendency to disturb them from their normal position or prevent their actuation when they should respond. The control relay GR is made so as to be exceptionally quick acting, and is provided with light contacts for controlling small currents; whereas the relays SR and ER, while also quick acting, are provided with heavier moving parts capable of controlling larger currents. In practice, these relays are resiliently supported in a suitable heavy spring supported casing, so that a large part of the vibratory disturbances are absorbed by this casing; but these details are not material to the present invention.

The car-carried apparatus also includes a cutout device CO for automatically cutting off energy of the car-carried apparatus when the railway vehicle on which it is mounted is out of service. This cutout device CO comprises a cylinder 180 provided with a piston 181 normally held in its upper position by pressure below this piston supplied directly from the main reservoir of the braking equipment, a compression coil spring 182 being provided between the upper side of this piston and the end of the cylinder 180, so that it the main reservoir pressure falls (ill to a predetcnmined low value the piston 1.81 will move downwardly, thereby moving the contact 183-3 from the stationary contacts (conventionally shown by arrows) and interru 'iting the main supply circuit of the carcarricd apparatus.

H" an engine and tender equipment equipped with the car-carricd apparatus, just described, laid up at the end of its run, in a roundhouse, or the like, the main reservoir prc sure will usually graduc-illy leak oti because the steam to the air compressors is shut oil'. As the main reservoir pressure falls below a predetermined value, the spring ot" the cutout device CO moves the piston It'll down and opens the contact 183, wl'icreby current is cut off of the various car-carried devices automatically. Before the engine can go back into service. .nlain re rvoir pressure must be brought up to said predetermined value whereby the .rnitomatic cutout switch again is closed to energize the several circuits of the car apparatus.

The car-carried apparatus also includes a air element or impulse receiver L, comprising a ll-shaped core 184 constructed of a good quality of laminated magnetic material terminating in enlarged pole pieces 185. One or" the of this core is surrounded by .a primary coil P for producing a large 1nagneto-motive-torce in this core and a corresponding field of flux emanating from the pole pieces 185; and the other leg is surrounded b a secondary coil S for controlling the control relay GR in a manner more fully described hereinafter.

Zmclmmy o f/j}(UGMMr-Tllfl train control system embodying the present invention is adapted to be used in connection with any one ol the wellknown types of signaling systems, or in connection with suitable manually controlled trackway devices, and for convenience the cm has been shown in connection with a typical commercial signaling system or the closed track circuit type. Although the system may be used in connection with distinctive aspect color light or position light or semaphore signals, for convenience it l been illustrated in connection with a sign, type. T he usual track rails 187 are divided. by insulated joints 188 to form divided blocks. Since the various blocks of the system are the same, the exist end of the block l and the entr "-"c cud to the block I only have been illustrated. The exit end of. each block is provided with a suitable source of on e conventionally shown as a battery 185), and the entrance end to each block is provided with a suitable track relay 190. These track relays 190 control the signals Z and have been shown conventionally without illustrating their well-known operating mechanism or control circuits.

no system of the semaphore Each of the blocks is provided with a plurality of pairs of track elements, only one pair of which has been shown. The first tract element T of each pair comprises a U-shaped core 191 constructed of a high grade of magnetic material, preferably laininated, and terminating in enlarged po e pieces 1%. A suitable distance in advance of this track element T there is provided a. similar but controlla le track element T", which comprises a similar core 191 provided with a coil 19%? on the back yoke thereof, which coil. normally closed in a circuit of low resistance, for reasons more clearly described hereinafter.

Adjacent each oat these pairs of track elements is provided a repeater track relay 1%, which has one of its terminals connected to the terminal 0 of a suitable source of energy, such as a battery, and has its other terminal connected to a line wire 195, which is connected through a front contact 196 of the track relay 190 of the next block in advance to the other terminal B of the battery.

These track elements or inductors T and T are preferably located at one side of the track, with their pole pieces a few inches above the level of the top of the track rails; and the receiver L is carried on the locomotive or other vehicle in position to pass over and come in superimposed relation to the track inductors L and T.

The locomotive or other railway vehicle has been conventionally illustrated by the axles 200 and 201; and on this vehicle are mounted the various elements of the carcarried system in suitable cooperative relation. On this railway vehicle is provided a suitable source of energy, such as one or more batteries, having a terminal B and having their other terminal connected to a common return wire 0.

Operation.

Norma (7 conditions.llnder normal condi tious ot' the apparatus, the primary coil P and the elcctro-pnemnatic device EPV are connected in series, the device EPV being shunted by a discharge resistance 5202. The circuit for energizing this primary coil 1 connected in series with the brake control device EPV may be t iced as tollows:--bcginning, at the terminal B of the car-carried battery. wire 203, contact 183 of the cutout device GO, wires 2th, 205 and 206, primaiy coil 1, wires 207, 208 and. 209, make-beforebreak contact Bhl, wires 5210 and ill, tront conta t 212 of the brake control relay 1%.? (which is placed in its energized position and maintained energized in a manner described hereinafter), wire 213, winding 77 ot the device l ll v, wire 214: back to the common return wire C. The tlow o't current in this circuit maintains the device EPV energized and energizes the primary coil P o in) to an extent to provide a suitable magnetoiuotire-force in the car element L.

The control relay GR is connected in series with the seconcary coil S of the car element L; and for reasons more clearly described hereinafter, the source of energy For normally maintaining the control relay (1R energized is derived by connecting it in multiple with the primary coil P, so that the voltage applied to the secondary coil and control relay GR is always proportionate to the voltage drop' across the primary coil P. The circuit for energizing this control relay GR and secondary coil S may be traced as follows :beginning at the terminal ot. the battery, wire 20?), contact 183 of the cutout device (10, wires 204, 20.3, 215 and 216, front contact 217 of the brake control relay BR, wires 218 and 2.19, tront contact 221 of the control relay CB, wires 222 and 223, winding of the control relay CB, wire 224, secondary coil S, wire 225 to the junction point between .the primary coil P and the electro-pneumatic valve EPV, namely, the wire 208.

The secondary coil S is, therefore, connected in series with the control relay CR by a partial circuit including the front contact of this control relay forming a shunt around the primary coil P, so that if a voltage is induced in this secondary coil S which reduces the flow of current through the control relay CR, this relay will drop its armature, thereby opening its stick Contact and its stick energizing circuit.

If the control relay OR is in its normal energizing position, a circuit is completed for energizing the secondary relay SB: starting from the terminal B, wire 203, contact 183, wires 204, 205, 215 and 216, front contact 217 of the brake control relay BR, wires 218 and 219, front contact 228 of the control relay CR, wires 229 and 230, lower winding of the secondary relay SR, wires 231 and 232, front contact 233 of the secondary relay SR, wire 234 back to the common return wire C.

\Vith the control relay GR in its energized position, an energizing circuit for the lower coil of the brake control relay BB is completed. This circuit is the same as the circuit for the lower coil. of the secondary relay SR from the terminal. B of the hat tery up to and including the wire from whence it comprises wire 235, lower winding of the brake control relay BR, wire 226 connected to the common return wire C. In other words, the control relay CR is connected in a stick circuit including its front contact and when in its energized position maintains the lower windings of the relays SR and ER energized, this circuit for the relay BR being non-stick but that for the relay SR being a stick circuit including the front contact 233 of this relay SR.

lVith the recondary relay SR in its energized position, as just explained, an energizing circuit for the time starting magnet TM is completed which may be traced as tollows:*beginning at the terminal B, winding 114-1; of the time starting magnet, wire 238. trout contact 233 of the secondary relay till, wire 234-. back to the common return wire With the time starting magnet energized, and the time-element device actuated to its normal position during the preceding resetting operation as heretofore mentioned, this time element device is main tained in its normal wound up condition.

i' llthough he brake control relay BB is adapted to be maintained in its energized position if the lower winding is energized by the c. curt heretofore traced, another or aux liary circuit for maintaining this relay in its energized position is energized by the following circuit under normal condition of the apparatus :--wire 2 contact 183 of the cutout device (7t), vii-es 204, 205, 215 and 210, front contact 217, wires 21S and 240, n r1nally closed contact 123 ot the time-element device, wires 241 and 242, the upper winding of the brake control relay BR, wire 213 to the junction point between the primary coil P and the brake control device EPV, namely, the wire 208.

It is thus noted that if the control relay CR is momentarily deenergized, thereby momentarily deenergizing the lower wind ing of the brake control relay BR, this relay will not assume its deenergized position it the time-element device is in the normal condition, because its upper winding is energized through the circuit just traced. Since, however, deenergization of the secondary relay SR decnergizes the time starting magnet TM, and since the secondary relay SR is also controlled by the control relay CR, it is evident that the normally closed contact 12?) will be opened shortly after the time starting magnet TM is deenergized, so that the brake control. relay 13R will be deenergized a short time after the control relay GR is energized, unless this control relay is again reenergized.

Passing first inductor T.Let us assume that the railway vehicle illustrated equlppel with the (air-carried apparatus shown in Fig. 1] in its normal condition, is moving along the block I with the block J unoccupied. As the vehicle moves along the block I, the car-carried element passes directly (iver the track element T in a manner so that the pole pieces 185 and 1.92 come in cooperative relation through a small air gap. This cooperation of the ear element L with the track element T reduces the reluctance of the magnetic circuit including the car element, so that a sudden increase ot magnetic flux through the secondary coil S takes place, this sudden increase of flu hi ing probably due to both a diversion of flux from leakage paths and an increase of the total flux passing tl'irough the primary coil P on account of the reduced reluctance of the magi'ietic circuit including the car element L. Also, as the car element L recedes from the track element T, the flu again changes back to its normal value. This sudden increase and decrease of the flux induces a voltage in the secondary coil S, similar to a single cycle of alternating current. The control relay CE is connected in circuit in a manner so that the first wave of this single cycle of elcctromotiive-force is in a dircction to reduce the flow of current to the control relay (JR, thereby momentarily deenergizing the control relay CR. Since the control relay Cit is connected in a stick circuit, it remains deenergized until reset through the back contact controlled by the secondary relay 8R.

lVith the control relay CE in its deenergized position because its stick contact 221 is open, decnergization of the secondary relay SR, controlled by the front contact 228 of the control relay GR, is effected. As soon as the secondary relay SR assumes its deenergized position, a pick-up circuit is closed for the control relay CR, which may e traced as follows :beginning at the terminal B of the battery, wire 208, contact 1.88 of the cutout device CO, wires 20%, 205, 215 and 216, front contact 217 of the brake control relay BR, wires 218 and 240, normally closed contact 123 of the time-element device, wires 24-1 and 2%, back contact 24:7 of the secondary relay SB, wires 248, 249 and 223, winding of the control relay CR, wire 224, secondary coils of the car element L, wire 225 back to the wire 208 forming a junction point between the primary coil P and electro-pneumatic valve EPV, so that the control relay CR again assumes its energized position whereby its stick contact 228 is closed to complete the stick circuit heretofore traced.

lVith the control relay CR again'energized, the secondary relay SR would again have been energized had its stick circuit in cluding front contact 233 not been broken. The secondary relay having been deenergized, as just explained, has interrupted the circuit for the time starting magnet TM so that the timeclcmcnt device has started on its cycle of operation, the control relay CR having, however, again been picked up through the circuit hcretofe'; ccd before the time-element device moved far enough to open the normally closed contact 128 of the time-element device. The time-element device now swings in the counter-clockwise direction, as indicated by the arrows on the timing contact actuators, until it has moved an angle of substantially 210 degrees, at which its inertia has been again ferred to the spring 10%, after which it returns almost entirely back to its original position depending upon the friction of the device.

After the time-element device has moved in a counter-clockwise direction through substantially an arc of i degrees, as shown by the distance of movement of the cam 181 necessary until it strikes the roller 127", a pickup circuit for the secondary relay SR is completed by the following circuit :wire 20 contact of the cutout device CO, wires 20%, 205, and 216, front contact 217 of the brake control relay BR, wires 218 and 219. front contact 228 of the control relay CE, wires 229 and 280, the lower winding of the secondary relay SR, wires 231 and 250, normally open contact 123 of the time-element device, wire 251 back to the common return wire C. The completion of this circuit causes the secondary relay SR to assume its energized position, after which the stick circuit heretofore traced through the front contact 228 of the relay GR is again completed, thereby permanently sticking up this secondary relay SR and in turn again energizing the time starting magnet Til of the time-element device.

its the balance wheel of the time-element device on the return swing carries the armature 108 w thin a small distance of the pole pieces of the starting magnet TM, the armature 108 comeswithin the influence of the flux emanating from the pole pieces of this starting magnet so that it is attracted to its normal position, thereby holding said armature and the balance wheel in the normal position.

It shou d especially be noted that through this cycle of operation the brake control relay BR has not been deenergized, because the normally closed contact 128 of the timeelement device has temporarily maintained this relay energized while the control relay CR was deenergizcd; and this control relay GR is immediately picked up by the back contact of the secondary relay SR, so that the EPV is maintained energized if a single impulse is received by the secondary coil 5 of the car e'cnient L while the timeelementdevice is normal. It should be understood that the contact operator or cam 134: is made of such length that there is time for the relay CF to be recnergized upon dropping of the relay Sit after the starting of the balance wheel which a so occurs upon deenergization of the relay SR.

Briefly sumi'narizing the various steps in the opcratiou'of the car equipment when a single impulse is received at the first active inductor of a pair and while the time-element device is in its normal or initial condition, the control relay CE- is first momentarily deenergized by the induced voltage secondary coil 55, by reason of its stick circuit this relay automatically remains deenergized until restored. The dropping of the relay LR interrupts one of the normally closed stick or holding circuits for the re ay BR and also doenergizes the relay SR, the relay BR being held up at this time by its other stick or holding circuit (including stick contact 217) through the normally cosed contacts 123 of the time-element device. The dropping of the relay SR, however, at once starts the time-element device, and. likewise causes recnergization of the control relay (It by the pick-up circuit through the back contacts of said relay SR and toe contacts 123 of the time-element device. the contacts 123 remaining closed long enough for the relay UR to again pick up. As soon as the relay GR is reenergized, and this happens before the contacts 123 of the time-element device open, the first stick circuit for the brake control relay BB is reestablished and this relay is maintained ener ized in spite of the opening of the contarts 123. At this stage in the operation, the relay CR, previously dropped, has been restored, the time-element device is in operation. and the re ay ER is maintained energized solely by its stick circuit through the front contact of the relay CR, the relay SR being still deenergized. As the balance wheel of the time-element device swings, contacts 193 are momentarily closed, ener izing the lower winding of the relay R, which is instantly energized and then maintained energized by its stick circuit through the front contact of the relay CR. lVith the relay SR reenergized, the magnet TM of the time starting device is energized and acts to catch and hold the balance Wheel as it ts bacl; to its initial or normal position.

The important point to be recognized is that thebrake control relay BR, after the reception of: the first impulse and so long v as the time-element device is operating and until the balance wheel returns to its normal initial condition, is maintained energized solely by its stick circuit through the front contact of the control relay CR, With the obvious result that. it the control relay GR is deenergized prior to the return of the balance wheel to its'initial condition, the relay Bl? is totally deenergized and causes a brake application.

Passing second aid actor. Clea?" condif /i())h.l.TJet us assume that the vehicle continues to move in the normal direction of traffic, as indicated by the arrow, and that it passes by the track element T. Since the block J is unoccupied and the relays 190 and '1 9iare energized, the coil 193 on the core of the track element T is closed in a circuit of low resistance by reason of the tact tl Under these conditions, only a very low single cyc e oi voltage is induced in the secit contact 194 is in its raised position.

ondary coil S of the car element. The reason for the induction of such a small voltage in a secondary coil S when the bucking coil 193 on the track element is closed in a circuit of low resistance, is believed to be due to the counter-magnetoanotive force set up by the current induced in this coil 193.

As the car element first comes into communicating relation with the track element, a slight change of flux takes place through the track element, thereby causing the flow of a heavy current in the coil 193. This current, by well-known principles of alternating current, is in a direction to oppose the magnetomotivc-torce producing it, so that only a very small change of flux through the track element takes place causing a similar small change of flux in the car element L. In other Words, the passage of a car element over a track element having its bucking coil closed in a circuit of low resistance does not cause an appreciable change in the reluctance of the magnetic circuit including the car element, so that only a small change of flux through the secondary coil S and the induction of a similar low voltage in this coil takes place. Since the present train control system is constructed on the premise that the reception of two control influences in less than a predetermined time causes a brake application; and since only one control influence has been received in passing over the pair of trackway elements shown in the block I, the train can proceed without an automatic application of the brakes for reasons just explained.

Passing second act Zoe inductor at proper spec .-Let us assume now that the train is moving through the block I in a manner just described except that the block J in advance is occupied by another train. Under this condition of the block J, the track relay 190 and the line relays 194 (only one being shown) are in their deenergized condition, and the second track element of each pair has its coil open circuited so that it will have the same effect on a car-carried apparatus as does the track element T.

Let us also assume that the train is mov- I ing at a speed less than the restrictive speed enforced by the pair of track elements T and T shown. As the car element L passes by the track element T, the control relay OR is deenergized, thereby deenergizing the secondary relay SR and starting the timeelement device upon its cycle of operation. Before the time-element device has moved far enough to open its normally closed contact 123, the back contact 247 of the secondary relay SR has closed a pick-up circuit, thereby reenergizing the control relay CR through its stick circuit and again completing the circuit tor the lower coil of the brake control relay BR, so that this relay Ill) and T, that is, by the time the time-element device Will have reached its normal position, and by reason of the reenergization of the time starting magnet TE before this second track element T is reached, the brake control relay BB is not deenergized so that the same cycle of operation may a 'ain. take place at the second. track element T, as

just described, Without causing an automatic application of the brakes.

Passing second inductor (it carcass-Zoe s,peecl.liet us assume now that the train is moving at an excessive speed in the block I when the block J- is occupied by another train, As the train in question passes the track element T, the time-element device is initiated upon a cycle of operation in a similar manner as heretofore expl lned. It should be noted that the normally closed timing contact 123 is open through substantially the entire cycle of movement of thetime-element device. the train moves over the second track element T, a similar impulse is received by the secondary coil S causing deenergiza'tion ot' the control relay GB. The dropping of the secondary relay SE in this event will not pick up the control relay CR, because the pick-up circuit for the control relay CR including the b1 3* contact 24:? of the secondary relay SR eludes the normally closed contact 123. of the time-element, device, so that the control relay GR, is left in its deenergized position. Also, the deenergization ot', the control relay CR1 deprives the lower, winding of the brake control relay of energy, and the opencondition of the time contact 123 deprives the upper Winding of the brake control relay BR of energy. This brake control relay BR, therefore, assumes its deenergized position, thereby breaking the main control circuit, including the front contact 217, of allthe relays, and also breaking the energizing circuit of the electropnc-umatic valve EPV, causing actuation of the brake valve actuator in a manner heretofore described to apply the brakes.

Resetting after automatic blfiitle applicati0 1t.After the train has been brought to a.

stop by the automatic brake application, the control apparatus may be reset to: normal and the brakes released by a suitable valve RY only accessible from the ground, sothat it may only be operated when the train is not in motion. This resetting operation con sists of operating the valve RV which applies pressure back of the piston 158 in the cylinder 112 thereby oper ting the rack and in turn moving the spring housing SH in a clockwise direction (as viewed from the top.) so as to, bring the armature 108 in communication With the pole pieces of the time starting magnet TM. The initial movement of the rack 156 causes the make-beforebreak ccntact mechanism MB to close the contact 167 and open the contact 168. Glosure of the contact 16'? completes a circuit for energizing the primary coil P, not including in series the device EPV. This circuit may be traced as follows :-beginning at the terminal B: oi the battery, Wire 203, contact 183 of the cutout device CO, wires 20%, 20-5 and 206, primary coil P, Wires 207, 208 and 209, front contact 167, Wire 255 back to the common return Wire C connected to the other terminal of the battery.

During this resetting operation, it Willbe observed that current is supplied to the primary coil P at the time the relay OR is reenergizcd. This arrangement is employed, rather than restoring the relay CR and thereafter applying current to the primary coil P, because it has been found that the application of current to the primary coil l3 and. the resultant increase in flux tends to cause the relay CR to open on account of the voltage induced inv the secondary coil S. By applying current to the primary coil concurrently Withthe energization of the relay CR, this. possibility is avoided; and on account oi? the malre-bstore-break contacts l6"? and 168, the current through the n'imary coil P is maintained Without interruption, being shitted from a direct connection to battery over Wire to the electropneumatic valve E331 ll ear the end of the stroke of the rack 15%, the switch operator l l strikesthe roller 163 tov opel: t e normally open reset switch DR, thereby closing pick-up circuits for the control. relay Cit and the secondary relay SR, respectively. These circuits comprise Wire 2023, contact 183 of the cutout device CO, 1

Wires 294,205, 215 and 256, movable contact 23, wires 25?, are and 223, winding of the control relay wire 22%,. secondary coil S, Wire 225 back to the terminal of the primary coil. 1 which is connected directly to the common return \vire C, through the make-bet'ore-break switch MB, this make-before-break sivitch being in its abnormal resetting position; and the pick-up circuit for the secondary relay SR is the same as the one just traced to and including the movable contact 1-23, from whence it comprises Wire- 258, upper winding of the secondary relay Sl t, Wire 259 back to the common return wire C.

The closure of the two pick-up circuits just traced causes the control relay Cit and the secondary relay SE to assume their energized position, thereby reenergizing the time starting magnet TM, and also closing an energizing circuit for the lower coil of the brake control relay BR. Also, at the end of the stroke of the rack 156 during the resetting operation, the armature 108 is brought into communicating distance with the pole pieces of the time starting magnet TM, but since this magnet is not immediately energized at the end of the stroke, the armature is not attracted until the secondary relay has been picked up by the completion of the pick-up circuits just traced. The closure of the time contact 123 at the end of the resetting stroke completes the energizing circuit for the upper winding of the brake con trol relay BR heretofore traced, so that both windings of the brake control relay BR again energized. Although the three relays CR. SR and ER are again energized and the time-element device is in its normal posit-ion, the device EPV :is still deenergized, for reasons presently. to be described. This is because the resetting apparatus is still in its active position, holding the make-before break contact BM in its abnormal position and energizing the primary coil i? by connecting it directly across the battery, instead. of connecting it in series with the EPV as heretofore explained.

If now the resetting valve RV is put back to its normal position, pressure is exhausted from the cylinder 112 and the spring 150 returns the spring housing SH to its normal position, thereby again moving the make before-break contact BM to its normal position, thus again connecting the novice EPY in series with the primary coil P and reenergizing it, whereby the engineer may manually release the brakes in a manner as heretofore explained in connection with the brake valve actuator. Itshould especially be noted that the device EPV is not energized while the resetting mechanism is in its active resetting position. This arrangement is employed so that the engineer may not permanently leave his resetting mechanism in its activecondition and thereby permit the train to proceed. along the trackway, that is, the device EPV may only be energized when the resetting mechanism is in its normal inactivecondition. After the train control apparatus has been restored to its normal condition, the engineer may proceed subject to the speed limits that may be on forced by a succeeding pair of inductors.

Change-over for freight and passenger.- Let us assume now that the car-carried equipment illustrated is to be used for freight service. This is accomplished by moving the passenger-to-freight set-up handie 11 to the dotted freight service position, whereby the brake valve actuator moves the brake valve in a manner so that the engineer may forcibly oppose and prevent an automatic brake application. This movement of the handle 11 also interrupts the circuit for the magnet 14% of the change-over 1nechanism CM, thereby releasing the additional weight 14-0 of magnetic material (serving as an armature) and causing it to rest upon the balance wheel 91 so as to increase the momentum of this wheel, thereby changing the time constant of the time-element device so that the train must consume a longer period of time in moving between successive track elements of a pair when pulling a freight train than when the engine is operating in passenger service.

It should be noted that the engineer can not set his brake valve actuator into the permissive or freight position without also putting the time-element device in its freight or slow speed condition. To a large extent, this in itself is protection against the possibility of the engineer setting the apparatus for passenger service when it should be set for freight service, because the engineer, by moving the handle 11 to obtain passenger speed limits, also sets the brake valve actuator so that the engineer can not prevent an automatic application by holding the engineers brake valve in the running position; and it is believed that, rather than having an unprcven'table automatic application of the brakes take place while pulling a freight train, the engineer would prefer to allow the permissive speeds intended for freight trains to be enforced. In other words, he would prefer to be provided with means for hold.- ing o'tl' an automatic application, rather than be permitted to move at a higher speed without the provision of such forestalling or preventing facility, so that the seal or locking means heretofore mentioned may be omitted, if desired.

Failure on side of safet i .i illhough intermitteut train control systems inherently function on the open circuit principle, in that an impulse from the trackway is neces sary to produce a stopping influence, the present train control system is substantially of the closed circuit t pe, because the magnetic quality of a body along the trackway is relied upon for the transmission of such a control influence, and this characteristic is unvarying and always present. An open circuit in the coil 193 of a trackway device T puts this trackway device in its active condition, so that it is constructed on the side of safety.

Referring now to the manner in which the normally closed circuit principle, or failure on the side of safety, has been applied to the car-carried apparatus, it will be noted that. the electro-pneumutic valve EPV is normally energized and requires a certain amountof current in its windings to maintain it closed and prevent the automatic operation of the brake valve actuator. ConlUU 

